Summary: Turbulence structure in thick layers of fluid.
D. Byrne, H. Xia, and M. Shatsa)
Research School of Physics and Engineering,
The Australian National University, Canberra ACT 0200,
(Dated: 19 April 2011)
Measurements of spatial structure of turbulence in thick fluid layers driven elec-
tromagnetically at small scales are reported. It is shown that at modest Reynolds
numbers the top sublayer behaves as quasi-2D and supports the inverse energy cas-
cade regardless of the layer depth. The cascade survives even in the presence of
strong 3D eddies developing in a layer whose depth exceeds half the forcing scale.
In a bounded flow at low bottom dissipation, the initial development of the inverse
cascade in the top sublayer, leads to the generation of a spectral condensate which
destroys 3D eddies in the bulk flow and enforces its planarity.
Electronic mail: Michael.Shats@anu.edu.au
There has been remarkable progress in the understanding of turbulence in fluid layers.
Such layers, characterized by large aspect ratios, are ubiquitous in nature. 2D turbulence